1. Field of the Invention
The present invention relates to a radar detecting apparatus for invoking a driver""s attention so that the movement speed of a moving body such as a vehicle does not exceed a stipulated speed, and more particularly to a radar detecting apparatus comprising a sensing wave detecting apparatus for detecting the presence of sensing waves and a position detecting apparatus for finding the current position of the moving body, such as a GPS (global positioning system), for example.
2. Description of the Related Art
The traveling speed of a vehicle is measured with a vehicle speed measuring apparatus (speed sensor), such as a portable xe2x80x9cspeed gunxe2x80x9d or fixed radar (or laser) measuring apparatus. A radar receiver for detecting the sensing waves of such a speed measuring apparatus receives the X band (10.525 GHz), K band (24.150 GHz), and Ka band (33.4 to 36 GHz), for example. The received frequencies cover a very broad range of frequencies and are in the high frequency band. For this reason, the first stage of the radar receiver is a mixer; a preamp and band-pass filter are not established in the first stage portion. A receiver with such a constitution does not include a band-pass filter for each received band and is therefore easily affected by jamming waves.
For example, even with a lower frequency signal, higher harmonics are generated because of the non-linear characteristics of the mixer stage when a signal with an intense level enters the mixer stage. This becomes a signal frequency such as X, K, Ka bands and causes the radar receiver to generate a false alarm. In an urban area, radio waves are used for automatic door sensors, traffic signal control, and so forth. Also, radio waves are used in vehicle distance sensors on vehicles. For this reason, when a vehicle travels through an urban area, it is easy for the radar receiver to generate false alarms frequently. As a countermeasure for this, a xe2x80x9ccity modexe2x80x9d is established to reduce the sensitivity of the radar receiver, for example, but at the same time, this also reduces the capacity of the speed measuring apparatus to capture sensing waves.
Accordingly, it is an object of the present invention to provide a radar detecting apparatus that is able to prevent false alarms due to jamming waves.
Also, it is another object of the present invention to provide a radar detecting apparatus that is able to prevent false alarms by storing the frequencies, reception power, reception location, and so forth of jamming waves transmitted from a fixed location.
In order to achieve the abovementioned objects, the radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates signal information relating to the electromagnetic wave signals upon detecting electromagnetic wave signals corresponding to prescribed conditions; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting the position information; first storage means for storing data; and a control portion for storing at least the abovementioned vehicle position information and the abovementioned signal information to the abovementioned storage apparatus.
The abovementioned travel position detecting portion preferably comprises a GPS receiving apparatus and outputs at least the latitude and longitude as the abovementioned vehicle position information. The abovementioned signal information preferably includes at least either the frequency or intensity of the detected electromagnetic signal.
Such a constitution makes possible the collection of data relating to jamming waves in the area in which an automobile is traveling.
Preferably, the abovementioned control portion references the plurality of signal information and position information data collected in the abovementioned first storage means, forms a map of the distribution of the electromagnetic wave signals in the area through which the abovementioned vehicle has traveled, and holds this map in the non-volatile second storage means. It thereby becomes possible to form a distribution map of jamming waves and to use this as a database. Moreover, the first and second storage means may be constituted with one storage apparatus. It is also possible to form such a database for each region and provide the database on an information storage medium such as a CD-ROM, DVD-ROM, or memory card. The database mentioned above, may also be provided online, for example, via a network medium such as the Internet or public telecommunications lines.
The abovementioned distribution map of electromagnetic wave signals preferably displays the area in which the abovementioned electromagnetic wave signals are present as a contour group that can be distinguished by the intensity and frequency of the signals. With the so-called contour representation, an area is classified by the intensity and frequency of the signal, making this representation easy to use.
The abovementioned storage means preferably store the abovementioned contour group according to the central position of the area represented by the contour and the distance from the central position to the contour. Storing information in such a format makes it possible to reduce the quantity of information stored (data compression).
In order to achieve the abovementioned objects, the radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates signal information relating to the electromagnetic wave signals upon detecting electromagnetic wave signals; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting the position information; a storage portion wherein locations of jamming waves causing false detection by the abovementioned wireless receiving portion and jamming wave information relating to the jamming waves are stored in advance; warning means for generating warnings; and a control portion for comparing signal information of the abovementioned detected electromagnetic signal and the jamming wave information, corresponding to the current location of the abovementioned vehicle read from the abovementioned storage portion on the basis of the position information of the abovementioned vehicle, and controlling the abovementioned warning means on the basis of the results thereof.
Such a constitution makes it possible to reduce the number of false alarms by comparing signal information for jamming waves stored as above, corresponding to jamming waves located near the travel position, with the signal information of detected electromagnetic wave signals; determining whether the electromagnetic wave signal comprises sensing waves or jamming waves; and stopping the generation of a warning when the electromagnetic wave signal comprises jamming waves.
The radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates a detection signal upon detecting electromagnetic wave signals corresponding to a detection reference; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting position information; a storage portion wherein locations of jamming waves causing false detection by the abovementioned wireless receiving portion and information relating to the jamming waves are stored in advance; warning means for generating warnings on the basis of the generation of the abovementioned detection signal; and a control portion for reading signal information when jamming waves are present in the vicinity of the position information of the abovementioned vehicle, and establishing (or updating, or changing) a detection reference for the abovementioned wireless receiving portion.
Such a constitution makes it possible to reduce the number of false alarms because of establishing detection reference for jamming waves, corresponding to jamming waves present near the travel position, and detecting sensing waves.
The radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising detecting means 100, 300 for searching the frequency bands in which the abovementioned sensing waves are present and generating detection signals upon detecting electromagnetic wave signals corresponding to prescribed conditions; travel position detecting means 200 for detecting the current position of the abovementioned vehicle and outputting position information; warning means 303, 304 for generating warnings on the basis of the generation of the abovementioned detection signal; storage means wherein the speed limit for the route traveled by the abovementioned vehicle is stored; and control means 300 for calculating the vehicle speed from the change in the abovementioned position information and the time difference and suppressing the output of the abovementioned detection signal when the vehicle speed does not exceed the abovementioned speed limit.
Such a constitution makes it possible to prevent the generation of unnecessary alarms when the speed limit is being maintained.
The radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates a detection signal upon detecting electromagnetic wave signals corresponding to a detection reference; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting position information; a storage portion wherein locations of jamming waves causing false detection by the abovementioned wireless receiving portion and information relating to the jamming waves are stored in advance; warning means for generating warnings on the basis of the abovementioned detection signals; a storage portion wherein the speed limit for the route traveled by the abovementioned vehicle is stored; and a control portion for reading signal information when jamming waves are present in the vicinity of the position information of the abovementioned vehicle, comparing that signal information of the jamming waves to already stored signal information relating to electromagnetic wave signals, calculating vehicle speed from the change in the abovementioned position information and time difference, and suppressing the output of the abovementioned detection signal when the vehicle speed does not exceed the abovementioned speed limit.
With such a constitution, unnecessary alarms are not generated in the case where the speed limit on the route is being maintained, even if the generation of false alarms due to jamming waves on the travel route is suppressed while speed sensing waves are detected, and the presence of the sensing waves is detected.
The radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates a detection signal upon detecting electromagnetic wave signals corresponding to prescribed conditions; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting position information; a storage portion for storing data; marker input means for generating a marker command signal in response to an operation; and a control portion for reading signal information in response to the generation of the abovementioned marker command signal, correlating the abovementioned marker command signal and the position information, and storing this correlation in the abovementioned storage portion.
Also, the radar detecting apparatus relating to the present invention is a radar detecting apparatus that is installed in a vehicle and that captures sensing waves emitted by a speed sensor, further comprising a wireless receiving portion that searches the frequency bands in which the abovementioned sensing waves are present and generates a detection signal upon detecting electromagnetic wave signals corresponding to prescribed conditions; a travel position detecting portion for detecting the current position of the abovementioned vehicle and outputting position information; warning means for generating warnings in response to the abovementioned detection signal; a storage portion for storing position information already correlated to a marker command signal; and a control portion for ordering a warning or the like from the abovementioned warning means or other signaling means, when the position information for the current position of the abovementioned vehicle matches or approaches the position information correlated with the abovementioned marker signal.
Such a constitution makes it possible to cause the radar detecting apparatus to generate a warning (or signal) at locations (points) in an area where attention should be paid. Moreover, the marker and position information may be input manually and in advance.
The abovementioned position information preferably includes latitude, longitude, and time. The abovementioned electromagnetic wave signals includes radio waves and laser beams and corresponds to speed sensors using radio waves and speed sensors using laser beams.
A database of information (position, field intensity, frequency, emission time, and so forth) on jamming waves along the vehicle travel route is formed for each region. This database is recorded on an information recording medium such as a CD-ROM, DVD-ROM, or MD (mini disk) or provided online, making it possible to reduce the learning load as the vehicle is actually traveling.